How effective is Contrave?
Contrave was studied in four clinical trials to evaluate whether it is effective for weight loss when combined with a reduced-calorie diet and increased exercise. Three of the trials included obese patients (BMI of 30 kg/m2 or greater) or patients with a BMI of 27 kg/m2 or greater and either high cholesterol or high blood pressure. The fourth trial included patients with a BMI of 27 kg/m2 or greater and diabetes.
A total of 4,536 patients were enrolled among all four trials and randomly assigned to receive placebo or Contrave at a dose of 32 mg naltrexone and 360 mg bupropion. At the start of the studies, the average weight for patients not enrolled in the diabetes study was approximately 220 pounds. The average weight for those in the diabetes trial was slightly higher at approximately 230 pounds. In each study, Contrave was started at a low dose and increased each week during the first 3 weeks. Once the desired dose was achieved, participants took Contrave or placebo for approximately 1 year in combination with either a 500 calorie per day reduced diet and exercise or an intensive behavioral medication program.
Participants in both the placebo and Contrave groups lost weight, but those randomized to the Contrave groups lost more weight compared to the placebo groups. In the study of patients that received Contrave in addition to a 500 calorie per day reduced diet, patients lost approximately 9 more pounds of body weight compared to placebo. In the study of patients that received Contrave and intensive behavioral medication counseling, patients lost approximately 7 more pounds compared to placebo. The highest weight loss was 18 pounds in the Contrave group and approximately 11 pounds in the placebo group. In the diabetes trial, the Contrave group lost approximately 4.4 more pounds compared to the placebo group.
Interesting Facts about Contrave
Contrave is the third anti-obesity medication to receive FDA approval in the United States since 2012 (Qsymia and Belviq were both approved in 2012).
Patients taking Contrave can receive access to personalized weight-management support at no cost from the manufacturer of Contrave.
Contrave should not be taken with high-fat meals because fat increases blood levels of Contrave.
Contrave can cause false positive urine test results for amphetamines.
What are side effects of Contrave?
The three most common side effects of Contrave are nausea, constipation, and headache. In clinical studies, nausea occurred in 32.5 percent of study participants receiving Contrave and 6.7 percent of participants who received placebo. Constipation occurred in 19.2 percent and headache occurred in 17.6 percent of participants receiving Contrave compared to 7.2 percent and 10.4 percent, respectively, of placebo patients. Other side effects that occurred in greater than 5 percent of Contrave patients were vomiting (10.7%), dizziness (9.9%), insomnia (9.2%), dry mouth (8.1%), and diarrhea (7.1%).
A small analysis of patients 65 and older noted that they were more sensitive to Contrave and experienced more sleep and psychiatric side effects (28.6% of Contrave patients vs. 6.3% of placebo patients). In general, these side effects were mild or moderate in severity.
More serious but less frequent side effects that required medical attention include kidney infections, inflammation of the gall bladder, and heart attack.
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